CINCINNATI -- The Washington Nationals could have a fortified bullpen Monday afternoon when they look to complete a four-game sweep of the Cincinnati Reds.

Right-hander Ryan Madson and left-hander Sean Doolittle, who were acquired in a trade with the Oakland Athletics on Sunday, might arrive for the series finale.

"With Madson and Doolittle, we get two quality human beings, first of all," Nationals general manager Mike Rizzo said. "Great teammates, guys who are experienced, guys with big stuff. Both are capable of getting the final three outs, which will help stabilize our entire bullpen."

Washington sent right-hander Blake Treinen and two minor-leaguers to Oakland in exchange for Madson and Doolittle.

It wasn't certain whether the pair would join the Nationals in Cincinnati on Monday or in Anaheim on Tuesday for the opener of a two-game set against the Los Angeles Angels.

The Nationals (55-36) will be looking to sweep the Reds in a four-game series for the first time since July 20-23, 1989, when they were still the Montreal Expos. Washington has never swept a four-game series at Cincinnati.

There is no guarantee Scooter Gennett will be in the lineup for the Reds on Monday. However, Gennett's numbers against Nationals right-hander Stephen Strasburg will force Reds manager Bryan Price to take a long look.

Gennett, who is having a big season after being claimed off waivers from the Milwaukee Brewers in late March, is 4-for-8 with a double, three home runs and six RBIs against Strasburg, including 2-for-3 with a double and homer against him in a 6-5, 11-inning loss at Washington on June 23.

Gennett, who went 2-for-4 with three RBIs in the Reds' 14-4 loss to the Nationals on Sunday, already has established a career high with 16 home runs. His 51 RBIs are the most by any player with as few as 213 at-bats, making his acquisition one Cincinnati's shrewdest moves.

"During my tenure here, it's got to be number one," Price said of the decision to claim Gennett off waivers. "I can't say you could see this coming, but it's off the charts what (Scooter) has done for the ballclub. Some really good decisions by our front office and scouting department, for sure."

In seven career starts against the Reds, Strasburg (9-3, 3.43 ERA) has averaged nine strikeouts per nine innings, but he is just 2-1 with a 5.00 ERA those games. On June 23 at Nationals Park, Strasburg allowed five runs on eight hits in five innings in a no-decision vs. Cincinnati.

The Reds (39-52) will counter with right-hander Scott Feldman, their most consistent starting pitcher this season. Feldman (7-6, 3.94) leads the staff in most categories, including wins, starts, innings pitched, strikeouts and quality starts. In his past six outings, Feldman is 3-2 with a 2.92 ERA and four quality starts.

In three career starts against the Nationals, Feldman is 1-0 with a 2.50 ERA, 16 strikeouts and eight walks in 18 innings. He has faced them once this season, allowing two runs on seven hits in seven innings during a 6-2 win at Washington on June 25.

Despite dropping the first three games of this series, Cincinnati has won six of the past 11 against the Nationals.